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The expansion of large pipelines can strongly affect fragile ecosystems in arid regions. However, the issue of oasis desertification due to pipeline construction has rarely been addressed. In this study, three parallel pipelines routed through the Zhangye Oasis located in the middle Heihe River Basin in northwest China were chosen as a case study, and the intensity and extent of the pipeline construction disturbances on oasis desertification were evaluated using satellite images. The results indicated that land desertification increased from 20,427 ha before the pipeline disturbance to 26,312 ha after the construction in the 5000-m buffer zone. The relative rate of land desertification was used to identify the cumulative impact of pipeline disturbance. The threshold distance of the first pipeline’s disturbance was 2000-3000 m. However, after the second and third pipeline installations, the threshold extended to 3000-4000 m, which may result from the cumulative impact of the incremental projects. The disappearance of soil and vegetation, and rivers across was the direct impacts of the pipelines’ construction on oasis desertification. Cutting and grazing along the ancillary road made for increasing reclamation led to indirect impacts of the pipelines’ construction on oasis degradation. To reduce the effects of pipeline disturbance on oasis desertification, the implementation of mitigation measures such as backfilling the removed soil, recovery of the local vegetation, retirement of the degraded cropland, limitation of ancillary roads, and cross-river cofferdam diversions are recommended for the environmental management of pipeline projects.